Can I buy a handgun in Nevada if you were arrested for domestic violence and later got it dismissed

While your facts are not entirely clear, a dismissed case should have no singificant after-effects, although you still have to answer the questions on the CCW application honestly, and if they trouble you, you may want to go through the steps to seal the case entirely, which permits you to lawfully deny that it ever existed.  If you have questions, consult with any criminal defense attorney, which is the field of attorney that deals with these questions most often.